Allsky Camera

- 4 mins read

An amazing aurora from the Valley

Intro

Living in the Huon Valley, in Southern Tasmania, I’m lucky to have some amazing night skies with the minimal light pollution, as well as amazing auroral displays semi-regularly, being 42 degrees South. In November of 2023 I decided to build an Allsky camera. If the camera is running, it is available at allsky.rigby.systems/allsky/

The Allsky Project is an open-source project started by Thomas Jacquin, with a few active developers maintaining and contributing to the project. I want to give a shout out to Eric Claeys who gave me a bit of assistance when I added support for a new camera. This project allows hobbyists to build astrophotography cameras which capture the whole sky. The software includes a configuration web server and public webserver, with the software building time-lapses, star trail and keogram images at the end of each night. Running on a Raspberry Pi, connected to a suitable camera, the software takes images all through the night, adjusting the exposure and gain to get really great photos of the night sky. Star Trails

Version 1

I built my first all sky camera using a Sony IMX462 sensor from arducam. This camera uses Sony’s STARVIS sensor technology, which is high sensitivity, low noise pixels. This translates to brighter stars for shorter exposure lengths, reducing smearing as the Earth rotates. Using an IP67 enclosure from Jaycar, an acrylic dome from Amazon, and some gasket paper from Repco, I built a housing and installed the camera out at the Huon Bush Retreats. I was lucky enough to capture an amazing timelapse of the Aurora of 12th May 2024: viewable below:

Version 2

Version two incorporated a few changes, first I switched to acrylic discs from the dome, I noticed that the dome suffers weathering from Tasmania’s harsh UV after a few months, so I thought that using cheap discs (bought about 30 for $20 on EBay) that could be swapped out after weathering would be good. Condensation was also accumulating on the inside of the dome so I designed a heater PCB to warm the lens. The biggest change however was designing the a solar power supply. I bought a 100W panel off EBay along with an LiFePO4. I also added an external WiFi antenna using a UFL connector soldered on the Pi, with a view to build a 3D printed parabolic reflector for the antenna, and a matching one on my house. This would allow the Allsky camera to be located further up the hill from my house where it wouldn’t get flashed by the high beams of drivers passing my house.

Being more than a little interested in UFOs, I also removed the IR filter on the camera. Pixels on visible light cameras are also sensitive to infrared light that is close to the visible light spectrum, and are fitted with filters to block infrared light. If you remove this filter then the camera sees infrared light as well: Infrared sensitive camera Apparently some UAPs (Unidentified Aerial Phenomena) known in the community as “orbs” are more/only visible in the infrared spectrum. Thus removing the IR filter will allow your camera to catch some UFOs with your allsky camera. The camera definitely saw more stars and more objects moving relative to the stars then with the filter, though none of the objects moved in a way that couldn’t be explained by satellites. The IR filter does somewhat like all real world filters isn’t ideal, so it does reduce the magnitude of visible light getting through. For capturing stars the filter removed is better. There is however a trade off. RGB pixels all have a second peak in the IR spectrum, this means that when you see an aurora, which also gives off a lot of infrared light in addition to visible light, it hits all the RGB pixels. This means that your aurora comes out as white in the imagery.

Not as spectacular as an aurora visible in just the visible spectrum. for this reason in V3 I’m returning to a camera with the “No IR” filter.

Version 3

Version 3 is incorporating a bunch of new features, and I’m in the process of building it. These include:

  • Camera head that can pan and tilt for looking around, and programmable motion over time-lapses.
  • Two 100W solar panels on a frame that pans and tilt so it can sun track. A couple of cloudy days on version 2 would result in it dying over night.
  • A GL.Inet 4G IoT modem so it can be placed anywhere with phone reception.
  • A frame that looks like a robotic probe that has landed on another planet, even with a fake rocket nozzle.